ErrorView+ErrorDisplayable.swift

// MARK: - ErrorDisplayable
extension ErrorView: ErrorDisplayable {

  static func show<T: ErrorView>(
    fromViewController viewController: UIViewController,
    animated: Bool = true,
    completion: ((Bool) -> Swift.Void)? = nil) -> T {

    guard let subview = loadFromNib() as? T else {
      fatalError("The subview is expected to be of type \(T.self)")
    }

    viewController.view.addSubview(subview)

    // Configure constraints if needed
    
    subview.alpha = 0
    subview.superview?.sendSubview(toBack: subview)
    subview.show(animated: animated) { finished in
      if finished {
        subview.playAnimation()
      }
    }
    return subview
  }

  static func show<T: ErrorView>(
    fromView view: UIView,
    insets: UIEdgeInsets = UIEdgeInsets.zero,
    animated: Bool = true,
    completion: ((Bool) -> Swift.Void)? = nil) -> T {

    guard let subview = loadFromNib() as? T else {
      fatalError("The subview is expected to be of type \(T.self)")
    }
   
    view.addSubview(subview)
    
    // Configure constraints if needed
    
    subview.alpha = 0
    subview.superview?.sendSubview(toBack: subview)
    subview.show(animated: animated) { finished in
      if finished {
        subview.playAnimation()
      }
    }
    return subview
  }

  func hide(animated: Bool = true, completion: ((Bool) -> Swift.Void)? = nil) {
    self.stopAnimation()
    let closure: (Bool) -> Void = { (finished) in
      if finished {
        self.removeFromSuperview()
      }
    }
    if animated {
      UIView.animate(withDuration: self.animationDuration,
                     delay: 0.25,
                     animations: { self.alpha = 0 }, completion: { (finished) in
                      closure(finished)
                      completion?(finished)
      })
    } else {
      self.alpha = 0
      closure(true)
      completion?(true)
    }
  }
}